Nick Holonyak

OSA Fellow Nick Holonyak, Jr. defied critics when he discovered a new alloy that would emit light in the red part of the visible spectrum, creating the world's first visible and practical semiconductor LED in 1962. 2012 marks the 50th anniversary of his discovery, which has led to a host of developments, from digital clocks to the lasers that make CD players possible to fiber-optic communication networks.